1. Field of the Invention
The present invention relates to a method of forming a multilayer hard mask, and more particularly, to a method including a treatment performed on a top surface of a first hard mask layer before a step of forming a second hard mask layer on the first hard mask layer and configured to remove impurities and form dangling bonds on the top surface of the first hard mask layer.
2. Description of the Prior Art
Recently, a multilayer hard mask including different material layers is used in the manufacturing process of gates in a semiconductor device for forming the gates with excellent properties such as complete profiles and sufficient height. The material layers of the multilayer hard mask may be formed by atomic layer deposition (ALD) processes for controlling the deposition thickness more precisely and uniformly. However, due to the deposition mechanism of the ALD process, tiny impurities might be formed on the surface of the deposited material layer, and defects might occur in the multilayer hard mask after the step of forming the subsequent material layer of the multilayer hard mask. Accordingly, the profile of the gates formed by using the multilayer hard mask may be influenced, and the electrical performance of the semiconductor device may be affected too.